Thecus N8900 series User Manual page 75

NOTE
With RAID level migration function, the limitation as listed below.
1. During RAID level migration, it is not allowed reboot or shutdown system.
2. The RAID migration from R1 to R5 or R1 to R6, the all services will
restart and volumes "iSCSI" is read only but "user data" is capable read /
write during operation.
NOTE
 Migrating a RAID volume could take several hours to complete
 The RAID migration feature is available while it is configurable.
The migration scheme below is based on Thecus IP
Storage products in maximum possible
combination. The other model which has less HDD
supported can refer web UI while RAID migration
operated.
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